www.bbe-moldaenke.de
AlgaeOnlineAnalyser
Harmful Algae monitoring 24/7
The best solution for the
Online Monitoring of Algae
Online, flow-through
measurement of microalgal
concentrations in rivers,
lakes and reservoirs
Photo: Swiss Federal Institute for Environmental Science
and Technology - Division of Hydrobiology/Limnology
What does the AlgaeOnlineAnalyser offer?
The AlgaeOnlineAnalyser is an instrument
for the rapid measurement of microalgae
using a flow-through chamber.
The AlgaeOnlineAnalyser is used in measuring stations and laboratories,
Tasks
▶▶ algae online analysis
▶▶ regulatory control
and monitoring
▶▶ environmental
monitoring
▶▶ limnological
questions
▶▶ Planktothrix
detection
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AlgaeOnlineAnalyser  |  bbe moldaenke ©
in fact anywhere where the online assessment of water quality of flowing
waters, reservoirs and of drinking water extraction is needed.
On board ships and integrated into complex analytical systems, the
AlgaeOnlineAnalyser determines biologically relevant data of commonly
travelled shipping routes. Further applications are in the detection of
the early stages of algal blooms, of ecological changes in diverse phytoplankton and in limnology, as well as in oceanology.
The purpose of algal class determination is the qualitative and quantitative detection and evaluation of the occurrence of particular types of
algae, particularly those which can be classified as potentially harmful.
This includes e.g. the cyanobacteria Planktothrix rubescens, which
increasingly occur in reservoirs used for drinking water extraction.
The measurement principle
MEASUREMENT
The AlgaeOnlineAnalyser continuously determines the algal content
of water based on chlorophyll fluorescence in real time and without
the need for sample preparation. The chlorophyll-a measurement is
used as an approximation of the biomass of the micro-phytoplankton
in the water. The measurement is based on the natural fluorescence of
the photosynthesis apparatus of chlorophyll using excitation by light
sources. Comprehensive excitation of all microalgae is made possible
by six different LEDs at particular frequencies.
▶▶ in vivo determination
in real time
The presence of characteristic pigments in the algae influences chlorophyll-a fluorescence. A complex spectral analysis leads to the allocation
of the fluorescence signal to particular algal classes. Up to five different
algal classes can be determined simultaneously.
▶▶ multi-spectral
excitation
▶▶ measurement of
up to five algal
classes
▶▶ Calibration at
factory
▶▶ method comparison
▶▶ highest sensitivity
In contrast to other commercially available chlorophyll measurement
instruments, the AlgaeOnlineAnalyser is calibrated using real algal
cultures.
The fluorescence measurement corresponds to the time-intensive,
wet-chemical chlorophyll analysis according to ISO 10260 and DIN
38412/16. However, in contrast to wet-chemical analysis, the AlgaeOnlineAnalyser needs no sample preparation and can even replace
The AlgaeOnlineAnalyser
measures 42 cm high
by 60 cm wide and
20 cm deep
the laborious method of cell counting with
a microscope.
Fluorometric determination using the AlgaeOnlineAnalyser is highly sensitive due to the
use of a low-noise photomultiplier.
„
With the AlgaeOnlineAnalyser
we always have the algal content of our waterworks intake
under control and can react
immediately if it becomes
too high.
“
Norbert Kellner
Department Head of Glüder Waterworks, Germany
bbe moldaenke ©   |  AlgaeOnlineAnalyser
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What else can the AlgaeOnlineAnalyser do?
FEATURES
Unique Features
▶▶ yellow substances
measurement and
correction
The integrated detection and correction of yellow substances eliminates the disturbing influence of fluorescent humic substances on the
chlorophyll measurement and improves the quality of the measurement.
Additional information on turbid matter is provided by the transmission
measurement, which is also used for the compensation of turbidity.
▶▶ transmission
measurement
▶▶ touchscreen
▶▶ integrated PC
database
▶▶ alarm threshold
values
▶▶ measurement of
photosynthesis
activity
All relevant data and measurement results are displayed on the touchscreen in the form of tables or graphs and stored in the database. The
parameter settings and the measurement process can be controlled by
using the integrated PC. Alarm values can be freely chosen by the user or
adapted to WHO guidelines. A calculation in cell/l is on your choice.
Extensive fluorescence measurements allow analysis of the photosynthetic activity of the available algae. The resulting numeric values indicate
the health of the algae and their photosynthetic performance.
The components of the AlgaeOnlineAnalyser
sensor
touchscreen
sample inlet
peristaltic pump
USB slot
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AlgaeOnlineAnalyser  |  bbe moldaenke ©
interfaces
Valve Control: the AlgaeOnlineAnalyser can analyse several water samples in
sequence using valves attached to several different inlet tubes. The results
allow direct measures to be taken to reduce undesired algae in e.g. sample
water, cooling water and aquaculture plants.
Remote control and operation of the AlgaeOnlineAnalyser is feasible from a
central computer system via the Modbus TCP/IP protocol.
The instrument is calibrated using pre-installed algal classes before delivery.
The algal cultures and the corresponding reference instrument are subject to
continual quality control.
The AlgaeOnlineAnalyser needs very little maintenance and uses a
cleaning mechanism in the measuring chamber. This ensures the removal
of particles and biofilms inside the chamber. Biofilms can reduce the excitation light and lead to continually worsening measurement results.
FEATURES
▶▶ alternating channel
measurements in
sequence
▶▶ remote data access
▶▶ algae breeding ex
works
▶▶ reduced maintenance
due to cleaning mechanism
Interfaces
Interfaces
The AlgaeOnlineAnalyser is equipped with a serial RS232 interface for data
export and for connection to an external computer. In addition to the serial
connections, the instruments can be integrated into a LAN network via
Ethernet and also has a USB (2.0) interface. Optionally, additional analogue outputs (in pairs) up to a maximum of 16 and relay outputs for alarms,
up to a maximum of 8 can be installed. A SDI 12 converter is available on
request.
▶▶ RS232
▶▶ Ethernet, USB
▶▶ analogue outputs
▶▶ relay outputs
A look inside the bbe AlgaeOnlineAnalyser
Details of AlgaeOnlineAnalyser measurements
Algae of a taxonomic class possess a similar composition of photosynthetic
pigments and thus have a typical in vivo fluorescence-excitation spectrum,
whereby the emission wavelengths of the measured fluorescent light
are between 680 and 700 nm. It is thus possible to allocate an algal species to a spectral algal class due to its fluorescence spectrum. In order to
obtain a meaningful fluorescence excitation spectrum, six LEDs are used
at frequencies of 370nm, 430nm, 470nm, 525nm, 590nm and 610nm,
respectively. The excitation wavelengths of the LEDs are adapted to the
absorption wavelengths of the light-harvesting pigments of different
algal classes: phycocyanin, phycoerythrin, fucoxanthin, peridinin and
chlorophyll. The excitation of the algal pigments is performed after a dark
adaptation by switching on the LEDs one after the other at high frequency. In
the phases in between these pulses, the fluorescence emission of the
MEASUREMENT
PROCEDURE
▶▶ chlorophyll
determination
of algal classes
▶▶ unique pigment
analysis via
multispectral
excitation
bbe moldaenke ©   |  AlgaeOnlineAnalyser
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chlorophyll is measured as an answer to the excitation. Spectra of different
algal classes of an algal sample consisting of cyanobacteria, chlorophytes,
the brown group, diatoms, dinoflagellates and cryptophytes are recorded.
A mean excitation spectrum per chlorophyll-a content (fingerprint) of an
algal class is determined. Using these “fingerprints” and a mathematical
operation (best-fit procedure) enables to calculate the chlorophyll-a concentration from a complex mixture and the distribution of up to 4 different
algal classes in a water sample. A fifth preinstalled class is reserved for the
detection of fluorescent yellow substances (humic substances) and their
use in the chlorophyll correction. Additional algal classes can be added
customized. The chlorophyll determination is quantitatively based on an
established HPLC separation method of algal pigments(1).
1 Wiltshire, K. H., Harsdorf, S.,
Smidt, B., Blöcker, G., Reuter,
R. and Schroeder, F.; The
determination of algal biomass
(as chlorophyll) in suspended
matter from the Elbe estuary
and the German Bight: A
comparison of HPLC, delayed
fluorescence and prompt fluorescence methods.
J. Exp. M. Biol. Ecol. 222, 113131 (1998).
2 Bernard Genty, Jean-Marie
Briantais and Neil R. Baker;
The relationship between
the quantum yield of photo
synthetic electron transport
and quenching of chlorophyll
fluorescence, Biochimica et
Biophysica Acta 990, 87-92,
(1989).
Principle of the activity measurement
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The light energy (photons) absorbed by the chlorophyll of the algal cell is used either for photosynthesis
or dissipated as heat or fluorescence. The processes
are linked in such a way that information on the photosynthetic performance of the algae can be derived
from the fluorescence.
becomes saturated with intense light, the photosynthetic process is limited and the fluorescence reaches
the maximum fmax within milliseconds. The difference
between fmax and f0 is called variable fluorescence and
reflects the maximum range of the use of light for photosynthesis.
The capacity of the photosynthetic activity is characterised by maximal quantum yield (energy input / maximum used energy in photosynthesis). After a dark
adaptation, the base fluorescence f0 is determined,
which represents low energy input when the photosystem receives only minor photons, i.e. when no more
photosynthetic products are made. If the system then
The photosynthetic activity is calculated by fmax - f0/
fmax , also known in the literature as the Genty factor
(a number between 0 and 1), which correlates to
oxygen release of photosynthesis. This factor is not
dependent on the chlorophyll concentration. When
algae are damaged by external factors, photosynthesis
is reduced and so is the Genty factor (2).
AlgaeOnlineAnalyser  |  bbe moldaenke ©
Software, specifications and scope of delivery
The software of the AlgaeOnlineAnalyser
Software
The AlgaeOnlineAnalyser uses the bbe++ software supplied. The main
functions are the operation, parameterisation and control of the instrument, data observation and the evaluation in the form of tables or graphs,
as well as the export of data and parameters in different formats (e.g.
Excel).
▶▶ graphic display
All parameters and data are stored in a database. The database can
store the data from different instruments and types. The raw data measured using the AlgaeOnlineAnalyser can be subjected to recalculation
using a changed parameter set. This recalculation (refit) leads to better
results when the basic algal class better fits the algae in the sample. Using
the bbe++ software new, different algal classes can be calibrated. The offset (zero value, blank) is also determined using the calibration function.
In batch mode, individual samples can be analysed. To do this, the
AlgaeOnlineAnalyser is completely filled with a sample and the measurement is started manually.
▶▶ table view
▶▶ parameterisation
▶▶ database function
▶▶ data export
▶▶ recalculation (refit)
▶▶ calibration function
▶▶ batch mode
▶▶ macro function
▶▶ alarms and
alarm thresholds
▶▶ test function
▶▶ operating system
Screenshot of the
AlgaeOnlineAnalyser
SCOPE OF
DELIVERY
▶▶ Instrument:
AlgaeOnlineAnalyser
The macro function contains pre-installed settings for a combination of
graphs and tables. This function allows the user to easily select commonly
used windows for display.
Alarm thresholds are configured for the individual algal classes or total
chlorophyll levels. Alarms are shown on the display and can trigger an
alarm (optional relay) or send a signal to the serial interface.
A test mode to check the functions of the hardware components of the
AlgaeOnlineAnalyser is also integrated.
The bbe software runs on all present-day Windows PCs. The touchscreen
PC of the AlgaeOnlineAnalyser uses a current Windows operating system.
▶▶ manual
▶▶ software
▶▶ network cable
▶▶ replacement tubes
▶▶ replacement fuse
▶▶ plugs for analogue
output / relay output
bbe moldaenke ©   |  AlgaeOnlineAnalyser
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BENEFITS
Technical Details
▶▶ Immediate analysis
of chlorophyll content
Description
Value
Measurements
total chlorophyll-a [μg Chl –a/l],
concentration green algae [μg Chl –a/l],
concentration cyanobacteria [μg Chl –a/l],
concentration brown class algae [μg Chl –a/l],
concentration cryptophytes [μg Chl –a/l],
yellow substances (relative units),
photosynthetic activity (Genty factor), transmission at 5 wavelengths, water temperature
Chlorophyll
0 - 200 µg chlorophyll-a/l
▶▶ long-term operation,
little maintenance
due to self-cleaning
antifouling
Measurement principle
spectral fluorometry
Resolution
0.01 µg chlorophyll-a/l
Transmission
0 - 100%, photometry
Photosynthetic activity
0-1 for > 3 µg chlorophyll-a/l
▶▶ calibrated using real
algal cultures
Cleaning function
cleaning piston
Housing
V4A steel/aluminium/coated steel plate
▶▶ evaluation of the
algal condition of the
flow-through sample
Weight
19 kg
Dimensions (H x W x D)
420 x 600 x 200 mm
Protection class
IP 54
▶▶ simple operation with
touchscreen PC
Voltage
110/240 V 50/60 Hz
Performance
100 W
Sample temperature
0 - 40 °C
Sample volume
30 ml
Maintenance interval
> 7 days
Sample feed
free pressureless inlet / peristaltic pump
PC
touchscreen PC 12” with Windows,
bbe++ software
Outputs
USB, LAN, R232
Outputs (optional)
modem, analogue outputs 4-20 mA up to 16,
relay outputs up to 8, SDI-12 converter, Modbus
TCP/IP
▶▶ Covers all algae classes with six excitation
wavelengths
▶▶ Adjustable alarm
thresholds
▶▶ prompt information on
cyanobacteria on-site
Do you have any questions? Please contact us!
Your local representative
bbe Moldaenke GmbH
Preetzer Chaussee 177
24222 Schwentinental
Germany
Tel.: +49 (0) 431 - 380 40-0
Fax: +49 (0) 431 - 380 40-10
[email protected]